1. Field of the Invention
The present invention relates to display devices, and more particularly to a border display device for simultaneously displaying a plurality of images on a display device.
2. Discussion of Related Art
Recently, voluminous amounts of visual information are transmitted through broadcasting channels. Moreover, the number of broadcasting channels continues to rise with more and more industries developing to meet the demands of viewers asking for a variety of information. In this multi-channel era, a picture in picture (PIP) technique is used to preview or search different channels while viewing another channel. Also, the possible range of a PIP use may be further extended in the future. This PIP technique uses a border for dividing and display of plural channels or images.
FIG. 1 shows a PIP border generated by a PIP technique in the related art. As seen, a typical PIP border is a monocolor of black or gray. Such PIP technique is used for both dynamic pictures and pictures in which a color or shading may rapidly change. FIG. 2 is a block diagram of a receiving system in the related art for displaying a PIP screen.
Referring to FIG. 2, a first tuner 201 selects a channel for a main image through an antenna and sends the selected channel to a main image processing unit 202. A second tuner 203 selects a channel for a secondary image also through the antenna and sends the selected channel to a secondary image processing unit 204. If the receiving system is a digital system and various programs are multiplexed in one channel, a single tuner can select and respectively output the selected channels for the main and secondary image.
The main image processing unit 202 decodes a main image signal to form a main picture and sends the main picture to a second multiplexer 206. If the secondary image is a PIP, the secondary image processing unit 204 performs down sampling in accordance with the PIP screen, and produces a PIP video signal and a PIP border signal.
A first multiplexer 205 multiplexes the PIP video signal and the PIP border signal using a synchronous signal of the PIP screen as a selecting signal, and sends the multiplexed PIP signal to the second multiplexer 206. Accordingly, the first multiplexer 205 outputs a PIP picture including a PIP border. The second multiplexer 206 multiplexes a main video signal from the main image processing unit 202 and a PIP signal from the first multiplexer 205, by using a synchronous signal related to the PIP border, and outputs the result to a display device, such as a monitor. Therefore, a main picture and a PIP-picture including a PIP border are simultaneously displayed on a display device.
However, in the conventional border display device, distinguishing the border between a main picture and a PIP picture may sometimes be difficult. This is apparent especially when a color around a PIP picture or shading of a main picture is similar to a color or shading of the PIP border. In addition, the PIP border may be visually too simple to meet the demands and tastes of viewers.
Accordingly, an object of the present invention is to solve at least the problems and disadvantages of the related art.
An object of the present invention is to provide a border display device capable of variously displaying a border to divide a plurality of images displayed on a screen.
Another object of the present invention is to provide a border display device that divides a border into a plurality of parts. More particularly, the object of the present invention is to give viewers a 3-dimensional (3D) or a cubic effect.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purposes of the invention, as embodied and broadly described herein, a border display device includes a shade processing unit converting a brightness and a difference of shade in a border in response to the border""s current brightness; an adder adding the border""s brightness and the shade difference produced through the shade processing unit; and a selector selectively outputting either the border""s brightness generated through the shading processing unit or the sum output by the adder, in response to a selection signal. A brightness of the border is a brightness included in the color signal of the border.
The shade processing unit includes a comparator comparing the border""s brightness with a preset threshold; and an operating unit outputting the border""s brightness and shade difference as received or converting and outputting the border""s brightness and shade difference, in response to the comparator""s output.
In the present invention, the border""s color and shading difference can be selected by a user. Furthermore, the border display device of the present invention may include a selection control unit producing a selection signal according to an area division from a width of the border and a synchronous signal of a border to be displayed, and sending the selection signal to the selector. The border""s width can also be selected by a user.